This invention generally relates to portable medical diagnostic equipment. In particular, the invention relates to equipment used to monitor patients during transport in a hospital or other patient care setting.
When providing medical care to patients, it is frequently necessary to monitor the patient using medical diagnostic instruments. One type of instrument, the patient monitor, is capable of monitoring the patient to acquire electrocardiogram data, cardiac output data, respiration data, pulse oximetry data, blood pressure data, temperature data and other parameter data. In particular, lightweight portable monitors exist which can be moved with the patient, allowing continuous monitoring during patient transport.
To facilitate monitoring at remote locations or during patient transport, modern portable patient monitors are powered by rechargeable batteries. Extended-use batteries, with quick recharge times, help maximize monitor availability. Advanced monitors have a smart battery management system which maximizes battery life, reducing maintenance and replacement. These patient monitors can also be plugged into any conventional electrical power system for use, e.g., at the patient""s bedside, before and/or after the patient is transported. At the bedside, advanced patient monitors can be hardwired to a central station via a local area network (LAN) for enhanced patient surveillance efficiency. In addition, the most advanced patient monitors have a built-in wireless option which enables the monitor to go mobile without sacrificing connectivity. Such monitors also support importation of demographic and laboratory data from a hospital information system for increased efficiency.
Portable patient monitors with integral battery power supply are commercially available in a compact, ergonomic package which allows easy handling. Typically such monitors have a drop-tested rugged design which allows them to withstand the punishment of the demanding intra-hospital transport applications. Mounting options make these monitors ideally suited for headboard/footboard, siderail, rollstand and IV pole use. The compact design is achieved in part through the use of flat display panels. The color or monochrome screen accommodates all numerics and multiple waveforms.
In addition to displaying waveforms and numerics representing the data being acquired, advanced patient monitors have a central processing system which stores and analyzes the acquired data. In particular, the central processing system is programmed with algorithms for analyzing the acquired data. The central processing system controls the transfer of data to the display panel for display and to the LAN via either a hardwired or wireless connection.
A critical feature of patient monitors is the ability to provide an alarm signal in response to detection of patient parameters indicating a medical emergency. Advanced patient monitors provide patient and system status notifications having different priority levels, such as Crisis, Warning, Advisory and Message. The notification is audible and/or visual. The alarm limits are user-selectable. Previous patient monitors could not visually alert a user who was not looking at the front of the monitor. This is a serious shortcoming particularly in large hospital wards in instances where the user is out of range of the audible alarm or the audible alarm is silenced. Existing auxiliary alarm lights are typically large dome lights that communicate with the monitor by being plugged into an auxiliary alarm connector on the back of the monitor.
The present invention encompasses the integration of a means for visually indicating an alarm condition, such as an alarm light, into the handle of a portable medical diagnostic instrument, such as a patient monitor, a portable oximeter, an ambulatory device for measuring non-invasive blood pressure, devices strapped to a patient for recording ECGs over time (e.g., Holter devices), a portable C02 measuring device or an EEG device. In accordance with the preferred embodiment, an alarm light is integrated into the top of the monitor handle. Since the top of the handle is the highest point of the monitor, the alarm light can be clearly seen from the sides, top and back of the monitor. Because the alarm light is integrated into the handle structure, it can be easily moved with the monitor and cannot be accidentally disconnected. In addition, the structure of the handle protects the alarm light from damage during transport.
In accordance with the preferred embodiment of the invention, an alarm light assembly is captured between two parts of the monitor handle during assembly. This alarm light assembly comprises a circuit board which supports at least one light-emitting diode and a connector for supplying electrical power to the light-emitting diode(s), and a light-transmitting plastic lens which supports the circuit board and is captured between plastic parts of the handle. The circuit board is impaled on a plastic heat stake integrally formed as part of the lens. One or more light-emitting diodes are disposed between the lens and the circuit board. When activated, the light-emitting diodes are visible through the lens.